Scientists make robot ray with gold and rat muscles

A team of Harvard scientists has created an artificial little stingray that can swim in a liquid based on light. The robot ray is made of plastic with a skeleton of gold and muscles of a rat heart.

The muscles are genetically modified to respond to blue light. Scientists at Harvard’s Wyss Institute for Biologically Inspired Engineering arranged the muscles in a zigzag pattern. Collapses create a repeating downward wave pattern, which forms the basis for the propulsion of rays. The upward pattern is provided by the skeleton of gold, which stretches and retracts like a spring based on the muscle movements.

The body of the robot ray is 16.3mm long and the weight is 10 grams. The maximum swimming speed is 3.2mm/s. Swimming does not take place in water, but in a liquid called ‘Tyrode’s salt solution’, which contains, among other things, glucose that serves as an energy reservoir.

The artificial ray is controlled by passing the liquid through one side of the creature with faster pulses than the other side. According to the researchers, their work opens the way to the development of autonomous artificial creatures that adapt themselves based on their environment. They publish their research in the scientific magazine Science.